Peel potatoes, cut into small cubes. Heat up broth, add potato cubes, white pepper, cumin. Bring to a boil, reduce heat and boil on medium low. After 30 minutes, puree the soup in a blender, return soup to pot. Keep hot, but don't let boil.

Cube avocado, distribute among two soup bowls, pour soup, add sour cream (2-3 teaspoons as desired). Chop parsley stems into small sprinkles, distribute among soup bowls, squeeze lime over soup as desired.